This relates to depth images. Depth images are captured by depth cameras. The depth image includes a two-dimensional (2D) depiction of the object together with depth data that indicates the distances of points on the object from the camera.
A depth camera may be used to identify and track an object. For example, it may be desirable to track hand movement in order to detect gestures made as inputs for computer control. In addition, it may be desirable to identify a user's face in order to identify the individual and/or to locate the user's eyes for purposes of gaze detection.
Connected-component labeling is a technique that may be used with image analysis to identify and track objects in two-dimensional depictions. Generally, connected-component labeling generates labels that identify distinct areas within an image. One of these areas may then be associated with an object to be detected in order to identify that object and, in some cases, to track the object.
However one problem in trying to apply connected-component labeling to more complex depictions, such as those involving three-dimensions including depth images, is that the extent of calculations in three-dimensions becomes a drag on the performance of the system. This results in increased processing time, slow operation and excessive battery consumption in some cases.